Internet Protocol Television (IP-TV) service providers multicast a large number of channels from a multicast source occupying a central location, to end-users in a multicast group through several network devices disposed between the multicast source and the multicast group.
Each network device has IGMP capabilities and replicates a multicast traffic according to demands coming from the end-users. In operation, when an end-user communicates a ‘join/leave channel’ request to one of the network devices, the request is propagated to the multicast source through each one of the network device disposed between the end-user and the multicast source.
In setting up or leaving a channel, the network devices disposed between the multicast source and end-users need to process the request. Significant latency takes place between the ‘join/leave channel’ request and channel delivery/removal. In an event of frequent channel changing by the end-user (known as channel zapping) this latency results in significant penalty.